From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4062 invoked by alias); 14 Oct 2014 10:08:18 -0000 Mailing-List: contact libffi-discuss-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libffi-discuss-owner@sourceware.org Received: (qmail 4045 invoked by uid 89); 14 Oct 2014 10:08:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Tue, 14 Oct 2014 10:08:16 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s9EA8CmB005981 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 14 Oct 2014 06:08:12 -0400 Received: from tucnak.zalov.cz (ovpn-116-116.ams2.redhat.com [10.36.116.116]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s9EA8A5Q014935 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Tue, 14 Oct 2014 06:08:11 -0400 Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.14.9/8.14.9) with ESMTP id s9EA89cq027763; Tue, 14 Oct 2014 12:08:09 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.14.9/8.14.9/Submit) id s9EA88BR027754; Tue, 14 Oct 2014 12:08:08 +0200 Date: Tue, 14 Oct 2014 10:08:00 -0000 From: Jakub Jelinek To: Andrew Haley Cc: pinskia@gmail.com, "libffi-discuss@sourceware.org" Subject: Re: Xeon Phi Message-ID: <20141014100808.GY10376@tucnak.redhat.com> Reply-To: Jakub Jelinek References: <543CE95A.9080409@redhat.com> <6442AADB-652F-443C-8875-258C0C1634D2@gmail.com> <543CEA22.9020302@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <543CEA22.9020302@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-IsSubscribed: yes X-SW-Source: 2014/txt/msg00120.txt.bz2 On Tue, Oct 14, 2014 at 10:17:22AM +0100, Andrew Haley wrote: > On 14/10/14 10:16, pinskia@gmail.com wrote: > > > > >> On Oct 14, 2014, at 2:14 AM, Andrew Haley wrote: > >> > >> What's the status of Xeon Phi support? There seem to be some packages on the > >> Interweb, but I don't see anything in libffi git. > > > > Xeon phi is just x86_64 linux. > > No it's not. There is a completely different FPU and a different ABI. I guess it really depends on which Xeon Phi you are talking about. There is Knights Ferry, which has been a prototype only, then Knights Corner, which is the one currently shipping, which AFAIK is a stripped down i586-ish (but 64-bit) ISA (so, no MMX/SSE and later, no CMOV and various other post-i586 ISA additions) with i387 FPU and a 512-bit vector unit. This isn't really supported by vanilla GCC, patches exist AFAIK for the non-vector unit part, but the vector unit isn't really supported in GCC. Not sure what exact ABI is this one using, supposedly some x86-64-ish ABI, just with what is passed normally in SSE/SSE2 registers is passed in the zmm? registers of the vector unit? Then there is going to be Knights Landing, see http://en.wikipedia.org/wiki/Xeon_Phi which is likely going to be pretty standard x86-64-ish ABI and ISA (contemporary Airmont), with AVX512F etc. extensions, fully supported by GCC. So, for the last one, I don't think any extra support is really needed (unless libffi has supports for AVX/AVX2 vectors already, then AVX512 support would be needed too). Jakub